312 Nuclear Forensic Analysis
step of the chemistry on this fraction is performed quickly, the equivalence assump-
tion
i
s
l
ess
i
mportant.
I
f
t
he
t
ime
b
etween
t
he
rst
s
eparation
a
nd
t
he
s
ubsequent
s
eparation
o
f
T
h
f
rom
R
a
a
nd
A
c
i
s
k
ept
t
o
a
m
inimum,
u
ncertainties
i
n
t
he
r
elevant
d
ecay corrections are minimized.
The
d
ry
R
a/Ac/Th/Am/Cm
f
ractions
a
re
d
issolved
i
n
8
M
H
NO
3
, evaporated to
d
ryness,
d
issolved
a
gain
i
n
8
M
H
NO
3
, and passed through fresh Dowex-1X8 anion-
exchange
c
olumns.
T
hese
c
olumns
ca
n
b
e
f
airly
s
mall
i
n
ca
pacity,
a
s
T
h
i
s
l
ikely
t
o
b
e
t
he
o
nly
a
nalyte
t
o
b
e
a
dsorbed
o
n
t
he
r
esin.
T
he
o
ther
e
lements
a
re
c
ollected
a
s
n
ew
R
a/Ac/Am/Cm
f
ractions.
T
horium
i
s
e
luted
f
rom
t
he
c
olumns
w
ith
9
M
H
Cl
a
nd
i
s another example of elution ion ex ...